This section is intended to introduce the reader to various aspects of art which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
A common problem inherent with digital imaging systems is that they are limited in the number of bits that can be displayed. In other words, their bit depth is finite. This limitation in the number of bits is a resolution limitation causing contouring in the displayed images. Essentially, the number of colors that may be displayed, as well as the range of light intensity, is limited, precluding the displaying of smoother images. In order to increase the resolution of the image display systems the bit depth needs to be increased.
In digital micromirror devices (“DMD”) using pixel shift technology, one parameter limiting the bit depth is the value of the least significant bit (“LSB”). The LSB represents the minimum amount of time that a pixel can be switched on for a given frame of video. One technique to achieve better bit depth or to increase the number of bits that can be displayed is to create fractional bits. Parameters such as light intensity may be controlled over time intervals shorter than the time represented by the LSB by, for example, attenuating the light source during the interval an LSB is displayed. However, once these fractional bits are achieved they must be scaled to the LSB in order to obtain a proper video to light transfer curve. Without proper scaling or calibration of the fractional bits, contouring within the image displayed may persist even with the increase in bit depth. Therefore, a system and method for calibrating or properly scaling these fractional bits to the natural LSB is needed.